Complications of High Frequency Jet Ventilation

High frequency jet ventilation (HFJV) has been introduced in 1967 as technique allowing ventilation with simultaneous access to the airway for bronchoscopy. Continuous improvement in the technique has led to a large use during interventional bronchoscopy, especially in large centers. However, complications occuring during the use of HFJV are poorly known. In this retrospective cohort study, the charts of all patients who had a bronchoscopy with the use of HFJV between 2019 and 2023 in our hospital will be analyzed. Primary outcome will the description of all complications during HFJV. Complications are defined as:

* Hypoxia: SpO2 < 90% for 1 min * Severe hypoxia: SpO2 < 85% for 1 min * Hemodynamic instability, defined as Arterial pressure < 90/60 * Cardiac arrhythmia * Laryngospasm or bronchospasm * Barotrauma or volutrauma * Need for ICU admission

A model predicting the risk for developing any complication will be developped using 2 mathematical methods:

* a multivariate analysis * a data mining approach

For both approaches, the following variables will be included in the model:

* Age * Gender * Weight * Height * BMI * Smoking * Alcohol consumption * Consumption of Other drugs * ASA class * Obstructive pulmonary disease * Restrictive lung disease * COPD status (1, 2, 3, 4) * Interstitial lung disease * Lung tumor

* Trachea location * Carina location * Bronchial location * Pulmonary or tracheal stenosis * Presence of stridor * Severe stenosis (< 6 mm) * Baseline SpO2 (pre-intervention) * Pre-intervention oxygen requirement Procedure * Duration (min) * Stent placement * Dilation * Laser treatment * Length of hospital stay Lung function tests * FEV1 (forced expiratory volume) * VC (Vital Capacity) * FEV1/VC (Tiffeneau ratio) * CPT (total lung capacity) * DLCO (carbon monoxide diffusion)